Samsung launched its Galaxy S4 smartphone back in April and the device has proven to be incredibly popular. It took the smartphone about two months to sell 20 million units and four months after launch to hit 30 million units. As the phone has aged and competition increased, it's sales pace has declined.

The Galaxy S4 sold only about 5 million units in August. However, Samsung CEO JK Shin recently stated that over 40 million Galaxy S4 smartphones have been sold globally since the device launched. Considering the phone is been around for about six months, this is an impressive feat for Samsung.

Samsung has continued to roll out some interesting new products following the launch of the Galaxy S4. Most recently, Samsung unveiled its Galaxy Note 3 and the Galaxy Gear smartwatch. The Galaxy Note 3 has impressed both reviewers and customers; however, the Galaxy Gear smartwatch has proven to be rather unloved in many reviews.